People in these areas have been urged to beware of the weather conditions.
The weather forecast for the next 24 hours is as follows:
Northern region: Cloudy with thundershowers in 70 per cent of the areas and isolated heavy rains; temperature lows of 24-26 degrees Celsius and highs of 30-35°C.
Northeastern region: Cloudy with thundershowers in 70 per cent of the areas and isolated heavy rains; temperature lows of 23-26°C and highs of 31-35°C.
Central region: Mostly cloudy with thundershowers in 40 per cent of the areas; temperature lows of 25-27°C, highs of 34-37°C.
Eastern region: Cloudy with thundershowers in 60 per cent of the areas and isolated heavy rains; temperature lows of 23-26°C, highs of 31-34°C; waves a metre high and 1-2 metres during thundershowers.
Southern region (east coast): Mostly cloudy with thundershowers in 40 per cent of the areas and isolated heavy rains; temperature lows of 23-26°C, highs of 33-36°C; waves a metre high and 1-2 metres during thundershowers.
Southern region (west coast): Mostly cloudy with thundershowers in 40 per cent of the areas and isolated heavy rains; temperature lows of 24-26°C, highs of 33-35°C; waves 1-2 metres high and two metres during thundershowers.
Bangkok and surrounding areas: Mostly cloudy with thundershowers in 60 per cent of the areas and isolated heavy rains; temperature lows of 26-27°C, highs of 32-35°C.